Stop mechanism.



W. o. STEWART.

STOP MECHANISM.

APPLICATION FILED MAR. 13, .1912.

1, M2 5 1 Q Patented May 9, 1916.

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APPLICATION FILED MAR. 13, 1912.

1, 1 $9 5 1 QB Patented May 9, 191

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7 SHEETS-SH W.C.STEWAR1H STOP MECHANISM.

APPLICATION FILED MAR. 13, 1912.

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I lgwii Patented May 9, 1916.

7 SHEETS-SHEET 3- W. C. STEWART.

STOP MECHANISM.

APPLICATION FILED MAR. 13. 1912.

1,182,510. Patented May 9,1916.

1 SHEET-SHEET 4.

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! STOP MECHANISM.

APPLICATION FILED MAR. I3, I912. 1,182,510, Patented Ma 9 1916.

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- STOP MECHANISM. APPLICATION FILED MAR. 13, 1912.

, Ii 7 1 82 5 l 0, Patented May 9, 1916.

7 SHEETSSHEET fiw. c. STEWART.

STOP MECHANISM. APPLICATION FILED MAR. 13, 1912-.

1,182,510 Patented May 9,1916.

1 SHEETS-SHEET z.

7%5265666 jmyrzfar em. @QW ZMiZiM W snares ra rnur orrion momma o. srnwnar, or LYNN, mnssncnusnr'rs, nssrenon To UNITED SHOE MACHINERY COMPANY,' pr PATERSON, NEW JERSEY, A oonronnrron or NEW teaser.

STOP MECHA NISM.

rgieasio.

Application filed Maren 13, 1912. Serial No. 683,616.

To 'allwhom it'mag concern:

Be it known that 1, WILLIAM C. STEWART, a subject of the King ofGreat Britain,- residing at Lynn, in the county of Essex and State of Massachusetts, have invented'cer tain new and useful Improvements in Stop fvfechanism; and I do hereby declare the following to be afull, clear, and exact description of the. invention, such as Wlll en I able others-skilled in the art to which it appertains to make and use the same. i

This invention relates to improvements in stop mech.nisms and more particularly to reversing stop mechanisms by which the forward motion of the shaft is arrested, and

the shaft is then given a reverse movement. to bring the partsof the machineto stopping positions.

"In many machines, particularly"in-' sewing and other machines employed in boot and shoe worln it is desirable upon the completion of the work to stop the machine always at a, certain and definite point in a cycle of operations. In certain machines it is desirableafter the forward movement of the machine is arrested to impart to the driving' shaft and thereby to the mechanism of the machine a reverse or return movement. In chain stitchv sewing machines this return movement is particularly desirable since by this movement the needle is caused to cast off the last loop thereon to permit the worlcto be withdrawn. Certain mechanisms have been devised for obtaining these desired results which act to yieldingly arrest the forward rotation of the shaft and then rebound to impart a return or reverse movement to the shaft. Such. mechanisms are usually'controlled by a spring or an air cushion and operate yicldingrlv to arrest the forward rotation'o-f the shaft throughthe vielding resistance of the spring or the air.

Mm the forward rotation. of the shaft is' arrested, the reaction orrebound of the spring or air cushion acts to impart a re verse 'movement'to the shaft. Since in machines provided with mechanisms of this type the speed of rotation of the shaft may vary between wide limits at the various times at wh ch the stop mechanism is thrown into operation. the speed of the return movement of the shaft imparted by the rebound of the spring or the air cushion var es also between wide llTIlliBS' It has therefore been 55 difficult to arrest thereturnmovement of Speci leation of I-etters Patent.

Patented May 9, 1916.

the shaft at a definite point in the rotation.

thereof without. undue shock orvibration.

The primary object of the present invention 1s to produce a stop mechanism by" which the forward rotation of a shaft may be arrested, a return movement imparted thereto, andthe shaft brought to rest at a predetermined constant positionin a rapid certain and reliable manner without undue shock or vibration. I With the above object in view, one feature of the invention contemplates. the provision in a stop mechanism of a rebound mechaa IllSIIl' acting to yieldingly arrest the forward rotation of the shaft to impart thereafter a return movement to the shaft and a' brake device acting in timed relation to the rebound mechanism to slow the shaft down to a predetermined speed before the arresting mechanism is brought into action. This provision insures that the shaft will always rotate ata constant speed during its return movement. Means is provided to cause the arresting mechanism to be brought intoposition atleast a predetermined interval after the brake is applied so that a material braking interval is secured. In the preferred form of the invention the rebound mecha "nism comprises a'cylinder and a piston arranged to operate in the cylinder and is constructed and arranged so that upon further forward rotation of the shaft after the parts ofsaid mechanism-areplaced in relative operating positions thepiston is operated in the cylinder to, compress the air therein. the air forming a yielding cushion acting to yielding'lv arrest the forward rotation of the shaft. When the forward rotation'of the shaft has been arrested the reactionor rebound of the air which has been placed under compression in the cylinder acts to force the piston outwardly. thereby imparting a the stop mechanism taken on the line H In the drawings illustrating the preferred form of the invention, Figure .1 is- 'a; view?cin side elevation of the stop vmeclianism applied to the main shaft of a welt and turn sewing machineo f a type well known in the art; liigsQ and 2 together constitute a View in side elevation of a portion-of the stop mechanism, certain parts thereof being shown in section; Fig. 3 is a plan 'of the stop mechanism; Fig. 4. ma sectional view of of Fig. 1', looking in the direction of the an rows; Fig. 5 is asection taken on the; line 5-5 of Fig. 2*; Fig. 6 is a plan ofa portion "of j the frame upon which certain 'partsof the stopping mechanism are mounted; Fig. is a sectional elevation'of the cylinder and p1s the base of. the machine and the'connections I between the treadleand the stop mechanism.

1h the drawings the stop mechanism has been illustrated as applied to the main shaft 1 of'a welt and turn shoe sewing-machine. Inasmuchras, the construction, arrangement and mode of operation of parts of the sewing machine of the, type illustrated in'the drawinga're well known to those skilledin the art, no'detailed description of the same is made herein.

In the drawings, the various-parts of the stop mechanism have been illustrated in the positions which the assume when the shaft .L i

a ver remains 1 n this posltlon throughout the has been brought to rest. The mechanism for arresting the forward rotation of the mam shaft 1 and for imparting'a return movement thereto comprises a lever '2 pivotally mounted on a shaft 3 and also arranged to slide longitudinally of said shaft. The forv ward end l of this lever overhangs the main shaft 1 of the machine and is formed with a cam surface 5, the forward portion of which is nearly concentric with the shaft 1 and the rear-ward portion of which curves inwardly toward said shaft. When the lever 2 is in the position illustrated in Fig. 4. and in full lines in Fig. 3, the forward portion of the lever lies in the path of a cam roll 6 mounted on the hand wheel 7, said hand wheel, being secured to the shaft 1 so to rotate therewith. When, therefore, the shaft 1 is ro-' tated in the direction of the arrow (Figs. 2?

and 2 and the lover 2 is in stoppingposition, cam roll 6 will engage the cam surface 5 of said'lcvcr and by the movement of the cam roll along. this cam surface the lever. 2 will be rotated to the left (Figs. 2 and 2") about the shaft 3. On account of the construction' of the cam surface 5, as above described, the angular movement of the lever 2 for the same angular movement of the shaft 1 increases rapidly as the cam roll 6 ap-' preaches the rearward portion of said sur- -a-valve 13 which is constructed to permit the entrance of. air into the cylinder but to prevent the exhaust of air therefrom through the said port. When the lever 2 is rotated in a left-hand direction (Figs. 2 and 2 by ins am face! The rear extremity 8 6f the lever 9 is connected by means of a. ball ended link 9 with a piston 10 which is arranged to' operate, in a cylinder 11. The said cylinder is provided with an'inlet port 12 controlled by theenga ement ofithe' cam roll fi with the cam sur ace .5, the piston'lO is -.moved inwardly in thecylinder 11 "compressing the air within the cylinder which forms a yielding and progressively increasing resistanceto the movement of the lever 2 and to the forward rotation of the shaft 1. When this resistance becomes sufiicient to overcome the momentumof, the machine the forward roe. tation ofthe=shaft 1 is arrested. Immediately thereafter the reaction or rebound of the air within the cylinder 11 imparts an outward movement to the piston 10 and through "the connection of the piston with the lever'2and the engagement of'cam'surface '5 on the lever with the cam roll 6 imparts areverse or a return movement to the shaft 1.

When the lever 2* is in the position indi cated in dotted lines in Fig. 3, the forward extremity of said lever is'out of the path of movement of the cam roll 6 so that said cam rollwill not engage the said lever. This is the position which thelever 2 is caused to assume in starting. the machine, and the le normal rotation of theshaft '1. In. order to trated in full lines to the position indicated in dotted lines in Fig.3, a lever 14 is mount- 5 ed upon a stud shaft 15 and is provided. with an upwardly extending arm 16 on which is mounted. a roll 17.. This roll is arranged to engage a cam 18 carried by a block 19 at.- tached to. the hub of the -lever 2'. Said 11 block is also provided with a surface 20 substantially parallel with the plane of movement of the lever 14. Then the parts are in-stopping positions as illustrated in the drawings and the lever 14 is swung to the left (Fig. 2) the roll 17 will engage the cam 18 and move the lever 2 to the position illustrated in dotted lines in Fig. 3. When the lever 14 is moved back to the position illustrated in the drawing the lever 2 will be returned to the position. shown in full lines in Fig. 3 by a coiled spring 21, mounted in a bore 22 inthe shaft 3 and engaging the block 19, the said spring being held in position with relationito said block by means "meaaio said lever andoperated by a foot treadle not shown. The rod- 25 is providedat its upper end with a slot 27 through which passes a pin 28 secured in the arm 26, thereby pro .viding 'a lost motionconnection between the i0 arm 26 and the treadle rod. l'V hen the lever 14 is' swung to the left (Fig. 2 a sufficient distance to carry the roll 17 on to the surface of the block 19 so that the lever 2 is moved to the position indicated in dotted 15 lines in Fig. 3, the lever 14: is latched in'position by a latch 29 pivotally mounted on the extremity of an arm 30 preferably formed integral with the: lever it, said latch being provided with a shoulder 31 which 0 drops behind a catch plate or bar 32. When the treadle is released the treadle rod moves upwardly under the influence of the spring connected with the treadle, andthe latch 29 is nnlatched from the catch plate 25 32b) a shoulder 25 on the treadle rod gaged by a coil spring which engages the under side of thelatch and lifts the'same. The lever 14' is then moved to the right (Fig. 2 by a plunger 33 mounted in shore in the frame an It is desirable that the devices for arresting; the forward rotation of the shaft be arranged to be thrown into relative operating positions always at a predetermined point ire-the rotary movement of the shaft in order that the stop mechanism may 21013 111 a 're-' liable and 'uniform manner in arresting the forward rotation of the shaft. imparting a return movement thereto and bringing the shaft to rest at a constant position. To insure these results a lever 35 is pivoted upon a stud 36 below the shaft 1 and is provided with a forwardly extending arm upon which is mounted a cam roll 37. This cam roll is held in engagement with the hub ,of the hand ivheel; 7 by a coiled spring 39 sur-, roundingthe stem of a plunger 10 mounted Y in a bore in the lever, the head of which engages a lug 41 on the frame,'said.spring acting against the head of the plunger and the end of the bore in the lever respectively. The hub portionof the hand wheel which is engaged by the roll 37- is cylindrical in form eiicept at one point thereon, atwhich point is formed a rise 42 constituting a cam which when it is brought into engagement with the roll 37 swings the lever 35 to the right (Figs. 2 and 2 The lever 35 is provided with a rearwardly projecting arm 43 constructed to form a catch 44;. The over His provided with an arm 45 preferably constructed integral therewith having a shoulder 46 formed thereon. llVhen the-lever 14 is swung to the left (Figs. 2% and 2 to throw the stop mechanism out of operation, the shoulder 4:6 on arm carried above the catch 44 on the lever 8o. With the level" 1st 111 ruiming position, and

with thelever S5 in the position illustrated in Figs. FZ 'andQ the shoulder $6 being lo cated above the catch a l, moyement of the lever l t to stopping position upon. the re lease 'of the shoulder 31 on. the latch 29 from the catch plate 32 is prevented by the engagement of the shoulder 46 with thecatch 4A Upon the engagement. however,-

.of therise 42 on. the hub of the hand Wheel 7 with the roll-37 the lever-'35 is moved to the right, (Figs. 2 and 23), carrying the catch at out of engagement with the shoulder 16 on the arm #15, permitting the lever 1a to more to the position shown in Fig. 2

so that the lever 2 may then move under the action of the spring 21 to stopping'position. t will'therefore be apparent that the devices for arresting the forward rotation of the shaft will be thrown into relative operating positi'ons' alwaysat the same point in the revolution of the main shaft 1 regardless of the time'atwhich the treadle is re leased. J

The roll-6 engages the lever-2 always at the same pointin a revolution of the main shaft, and the'devices for arresting the forward rotation of the shaftare therefore always brought into action at the same Pointin a revolution ofthe shaft.

its above stated it is desirable after the forward rotation of shaft has been arrested and a return movement has been imparted thereto to free the threadfrom' the needle to stop the shaft always at a'certain and definite point in the rotation thereof; To this a brake lever 4t? is pivotally mounted upon a stud 4S and carries a brake shoe 19, arranged to engage a rise 50 formed on a cylindrical flange constituting apart of the hand wheel 7. The brake shoe is pivotally connectedwith the lever 4? by the pin 51 arranged so that when the brake shoe is in engagement with the rise 50 the axis of the brake shoe 19 will be slightly in advance of the line connecting;- the axis of the lever 48 and the the shaft 1. With this construction when the shaft 1 has been reversed and the rise 50 has been brought into engagement with the brake shoe. the brake shoe'will be forcedtightly into engagement with the surface of the rise by the friction between the rise and the shoe. The rise 50 is located in a definite predetermined position with relation to the main shaft 1 and to thea-ise The ro verse movement of the main shaft 1 is therefore always arrested at a definite predeterinin'ed point in a rotation of the shaft 1 and in a cycle of operations of the machine.

.The lever 47 is swnngto the left (Figs. 2? and2 to bring the brake shoe 19 into position to engage'the rise 50 by a plunger plunger 33 is mounted, -and; 'also operated by the spring" 34. The. movement of said lever to the left is "limited by a stop 53 brake shoe 49 into'position the lever 2.

which is engaged by an arm 54 on, thelever. When the lever 14 is swung to the. left (Figs; 2*- and 2 from ,stoppingto running position, the lever 47 is swung to'thw 'ight to: carry the brake 49 out of engagement with the surface of the rise 50 by the-engagement of the end of the arm 30 witha surface 55 on the. lever 47. When the lever 14 is swung fromrunning to stopping position the arm 30 moves to the left, permitting the lever 47 to swing to the left under, the action ofthe spring 34 to bring the to engage with tl1e'rise50.

In the mechanism described it will be ap'parent'that the movement of the cam roll 6 'alongthe surface 5 of the lever-4, the

movement. of the lever 2 about/the stud 3, and

the extent of compressionof the air within-the cylinder 11 due tov the inward movement of the piston connected. with said lever, will depend on the'speed at which the shaft 1 is rotating at the time that the rebound devices are brought into action. The velocity of the return movement of the'shaft l which depends upon the compr ssion pro du'ced'in the cyiinder ll will vary with the velocity of the forward movement of the shaft latthe time that the .roll 6 engages It will also be apparent that variations in thevelocity of the return movementof the shaft will tend to produceavarie ations in the positions atwhich the reverse movement of the shaft is arrested by the brake mechanism... It is assumed, however,

that during the operation of the machine,-

trated, the said device comprisesa pair of centrifugal clutch members 57 and 58 pivotally mounted on studs 59' and 60 carried by the hand wheel 7 and provided with weighted extremities 61 and (32 respectively. Clutch shoes 63 and (A are mounted on the members 57 and 58 respectively and when -the said members are thrown outwardly by centrifugal action the clutch shoes engage an inner clutch surface (35 upon a. brake wheel 66 mounted loosely on the shaft 1. The clutch members 57 and 58 are connected ieaaio by a link 67 so that they move outwardly and inwardly into and out of engagement ;with the clutch surface in unison.

coiled spring 68 is connected at one end with the weighted extremity of the member '58 and at the other end with arelatively fix'ed point on the hand wheel, the tension of which springis just sufficient to main tain the clutchishoes 63'and' 64withdrawri from engagement with the clutch surface 65 when the speed of rotation of the shaft 1 equals or is less than a certain predetermined speed, but to permit the members 57 and 58 to be thrown outwardly to bring the clutch shoes into engagement with said brake extremity thereof fixed at 71 to the frame of the machine. A block'72 is secured to the other extremity of the brake band, and a rod '73 is threaded into said block and passes through perforated lugs TL and 75 projecting from the frame. A coiled spring 76 surrounds the rod 73 below the lug T4: and engages said lug and an adjustable collar 77 mounted upon the rod '73, thereby tending to move the rodj73 in a direction to-tighten the brake band 70. 'The collar 7 7 is held from longitudinal movement on the-rod 73 by a pin. 78 which may be placed in any one of a series of holes in the rod. The rod 73 is held from turning movement in the lugs H and 75 by a pin 79 which operates in a slot in the lug T5.

lVhen the parts of the stop mechanism are in running position the brake band is maintained in a loose condition about the brake wheel (56 by an arm 80 secured to the lever l-l so as to move therewith about the stud 15. Upon movement of the lever- 14: to the left (Figs. 9. and 2") to throw the parts of the stop mechanism out of operating positions. the extremitv of the arm 80 engages a collar 81 fixed to the rod 73 and moves the rod 7 :3 up'wardly through the lugs 74. and and thereby loosens the brake band. 'hen the lever It is in its extreme left-hand position the shoulder .46 is somewhat above the catch 4% so that upon the release of the treadle a slight movement of the. lever 14 to the right is permitted before the shoulder +6 engages the catch -14. This I movement of the lever It is sutlicientto carry the extremity of the arm 80 out of engagement with the'collar S1. and the brake band is then immediately tightened about the brake wheel by the action of the spring 7 6. Therefore the brake mechanismis applied to the shaft immediately .upon the release of the treadle. to the cam roll 6 is such that theshaft 1 must make at least substantially .half a revolutionafter the lever 2 is thrown into operative position-before the roll 6 engages the cam surface of the said lever. The shaft therefo'remakes at least half a revolution after the release of the treadle and the apf"ii31011 of the brake before the mechanism 3m: arresting the forward rotation of the shaffi is br ught into action, thus securing is a maturial braking interval. Assuming that the shaft is rotatingat a speed greater than that which is necessary to throw the clutch shws 63 and 6 1 into engagement with the (:ililuli surface 65 when the treadle is released, the sad clutch shoes wlll'be maintaincd in engagement with the said clutch surface and will tend to rotate the brake wheel 66 against the braking action of the .brake'band 70 until the shaft is rotating at the predetermined speed, when the clutch shoes will be withdrawn from engagement with the clutch surface of the brake wheel,

thereby releasing the shaft from the brakeand permitting it to continue to rotate, at

the predetermined speed by reason of the inertia of the machine. In case it is desired to increase the minimum braking interval secured, the relative positions of the roll 6 and'the rise 42 may be changed so that y the shaft will. make at least nearly a com-- plete revolution after the treadle is released and the brake applied before the roll 6 engages the surface 5 of said-lever.

It is desirable on certain occasions to turn the main shaft of the machine by hand to operate the parts of the machine, or to place the parts thereof in any desired po- .sition.

When the parts of the stop mechanism are in stopping positions it is impossible to impart more than a partial rotation in either direction to the main shaft of the machine. In order to throw the parts of the stop mechanism into starting position without depressing the treadle and thereby throwing the machine into driving connection with the driving shaft, a lever 82 is pivotallv mounted on the stud 48 and is provided with an upwardly extending arm 83 on which is mounted a roll 84: arranged to engagethe under surface 85 of the arm 15 of the lever 14. The lever 82 is also provided with a forwardly extending operating arm 86. "When the said lever is swung to the left (Figs. 2 and 2 the lever 14 1s swung to the left to throw the parts of the stop mechanismyinto starting position by the engagement of the'roll 84 With the un der surface 85 of the arm 45,.the slot 2': 1n

the-upper end ofthe-treadle rod permitting The relation of the rise 42' thetreadle to be maintained released pow sition. When the lever 14: is moved to its extreme left-hand position the roll 84- en tersa recess 87 behind the surface 85 and 'locks the lever 14 and the parts connected therewith in inoperative position.

' During the sewing operation, the machine is driven by means of a belt 88 passing about the hand wheel 7, and about a pulley 89 mounted in the base of the machine. The

pulley 89 isconnected through beveled gears 90v with a sleeve 91 mounted on the driving shafi'92, and carrying one member 93 of the main driving clutch. The driving shaft carries the other member 94* of the clutch,

and also carries the driving pulley 95,

through which motion is imparted to the driving shaft. The engagement of the members of the driving clutch is controlled from a treadle96 connected by a link 97 with a clutch operating wedge 98. When the treadle is released, the chitch members are;disengaged','thus disconnecting the main shaft of the machine from the driving shaft 92. Connecting mechanism is provided between the treadle 96 and the rod 25., so that when the treadle is depressed the parts of the stop mechanism will be thrown into running positions, and that when the treadle is released the stop mechanism will be thrown into operation. in the construction illustrated, the lower end of the rod 25 is. secured within a collar or sleeve 99 which is pivoted to the end of an arm 100 .fast upon a rock shaft 101 mounted inbearings 10:2 and 103 on the frame of the machine: 'A second arrn 104: is fast to the forward end of the rock shaft 101, and is connected by a rod 105 to the forward end of the ii i drawings. as the operator depresses the trcadle to start the machine, the lever 14, through its connection with the trcadle, is, swung to the left about the shaft upon which it is pivoted, thereby throwing the lever 2 longitudinally of the shaft 3 .out of the path of the cam roll .6. and disengaging the brake shoe 49 from the rise 50. Asthe lever 14.- swings to running position, the end of the arm 80 acts to lift the collar 81 and thereby loosenthe brake bands 7 0 about the brake wheel 66. -While the machine is running, the brake shoes 63 and 64 are engaged with the brake wheel 66, and the brake.

ise

' wheel is thereby rotated at the same speed afi'ectingthe lever 14:. Uponthe release ofv as thatof the main-shaft of the machine. The lever-leis held in running position by the engagement of the shoulder 31 behind fthe catch plate 3 2, and the slot 27 permits the pressure upon the treadle to be varied.

to change the speed of the machine without the treadle by the operator at the comple'- tion of thesewing operation, it rises under the influence of its actuating spring until the shoulder *v on the treadle rod engages beneath the-,end of the latch 29, thereby lifting the latch and disengaging the shoul-' der 31 from behind the catch plate 32. The lever let is thereby released, and is swung to the right by the action of the spring 34 until its movement-is arrested by'the engagement. of the shoulder 46 with the catch 44 carried by the lever 35, which is-then in the position shown in Figs. 2 and 2 The movement-of the lever'l from the position in which it is held by the latch 31 to the position in which it is stopped by the catch 44 is not sufficient to permit the cam lever 2 to'be moved into the path'of the cam roll 6, but is sufficient-to release'the end of the arm 80 from the collar 81 and allow the brake band 70 to be-tightened upon the brake wheel 66 bythe action of the spring 76.- The braking devices which act to reducethe speed of the shaft'to a predetermined speed beforelthe rebound devicesare thrown intov operation therefore become ac tive almost immediately upon the release of the treadle. As the main shaft of the ma-' chine continues torotate, the rise 42 is engaged by the roll 3.7, thereby swinging the lever 35 in a direction to disengage the catch 4:4: from beneath the shoulder 46. The lever 14 is then swung, farther to the right,

until it reaches the position shown in Figs.

2 and 2*, allowing the. cam lever 2 to be moved longitudinally of the shaft 3 into the {path of the cam roll 6, and releasing the lever 47, which issWung on its pivot by the action of the spring 34 to bring the brake shoe 49 into position to engage the rise 50.- Before the cam roll 6, however, engagesthe cam lever 2, the speed of the main shaft of the machine will have been reducedjto a predetermined speed by the coiiperative action of the brake shoes 64:, the brake wheel 66, and the brake band '70. .Upon the engagement of the cam roll- 6 withthe cam lever 2, the cam roll is swung about the. shaft 3 in a direction to cause the piston '10 to compress the air within the cylinder 11. When the resistance of the air within the cylinder is sufiicient to overcome the momentum of the machine, the forward rotation of the mainshaft of the machine is arrested. The reaction of the compressed air within the cylinder then forces the piston upwardly in the cylinder, and the lever 2 is thereby, swung in the" reverse direction. During this'movenient of the lever'"through the cooperative action ofthe camsurface .5 of the lever and the calnroll 6, a reverse rotation is imparted to the shaft. 'aliteverse rotation of the shaft is arrested-ate prede- I termined point by the 'eng gernent' ofthe brake shoe 4-9 with the 'rise50 i 'lfiavingexplained the nature and object of the invention, and specifically described one form of mechanism in which it may be embodied, what I claim-is 1. y A, stop mechanism, i

arresting the forward rotationof the shaft and for imparting thereafter a return movement to the shaft, and abrake device acting in timed relation to the rebound mechanism to slow theshaft-down to a predetermined speed before the rebound mechanism is brought into action,- substantially as de scribed. T 1

to the shaft, a brake device for the shaft,

means to apply the brake, and mechanism acting automatically to bring the rebound,

devices into action at least a predetermined interval after the brake is applied, substantially as described.

. having, in com-Q bination", ashaft, a rebound mechanism for 4:. A stop mechanism, having, in co,m-

bination, a shaft, mechanism for arresting the forward rotation of'the shaft, a brake device acting to slow the shaft down to a predetermined speed and then to release theshaft, means to apply the brake, and mechanism acting automatically to bring the arresting mechanism into action at least a predetermined interval after the brake is applied, substantial lyas described.

5. A stop mechanism, having, in combination, a shaft, devices for arresting the forward rotation of the shaft, a brake device acting to slow the shaft down to a predetermined speed and then to release the shaft, mechanism for applying the brake, and means to bring the arresting devices into action at a definite point in the rotation of the shaft after the brake is applied, said devices and means being constructed and arranged to maintain said devices out of action at least a predetermined interval after the brake is applied, substantially as described. 1

6. Astop mechanism having, in combination, a shaft, rebound devices for arrest termined constant position substantially as described. v l

T. A stop mechanism, having, 1n combination, a shaft, mechanismfor arresting the forward rotation of the shaft comprising a movable member having a curved cam surface formed. thereon, extending,

about the axisof rotation of the shaft in a directionsubstantially parallel with the plane of rotation of the shaft, a'second member mounted to rotate with the shaft and arranged to engage the cam surface of the first member and move said member, and means to yieldingly resist the movement of the first member, substantially as described.

8. A stopanechanism, having, in combination, a shaft, a rebound mechanlsm for arresting the f0rward'rotation of the shaft and for impartingthereaftera return movement thereto comprising a movable member hav ng a curved cam surface formed there on, extending about the axis of rotation'of the shaft 111 a direction subst-antlally-parallel with the plane of rotation of the shaft, a second member mounted to rotate with the shaft and arranged to engage the cam surface on the first member and move said member in one direction, and mechanism acting to yieldingly arrest the said movement of the first member and tothereafter move said member in the opposite direction to impart a return movement to the shaft, substantially as described.

9. A stop mechanism, having, in combination, a shaft, mechanism for arresting the forward rotation of the shaft and for. imparting thereafter a return movement.

thereto comprising an oscillatory lever pivoted on. an axis substantially parallel with the axis of rotation ofthe shaft and having a cam surface formed thereon, a

roll mounted to rotate with the shaft and arranged to engage the cam surface of the lever to move the lever about its axis in one direction, a pneumatic device acting to yieldingly arrest the-said movement of the lever and to impart thereafter a movement of the lever in the opposite direction to impart a reversemovement to the shaft, substantially as described.

10. A stop mechanism, having, nation, a shaft,mechamsm for arresting the forward rotation of the shaft, a brake deivice to slow the shaft down to a predetermined speed before the arresting mocha in combinism is brought into action comprising a member, mounted to rotate with the shaft and arranged to be thrown outwardly when the shaft is rotating above the predetermined speed, a second member arranged to be engaged by said first member upon out-, ward movement thereof, and means to withdraw-said first member from engagement with the second, member when the shaft is rotating at or below the predetermined speeed, substantially as described.

11. A stop mechanism, haiing, in combination, a shaft, mechanism for arrestingthe forwardrotation of the shaft, means to slow the shaftmlown to a predetermined speed before the arresting mechanism is brought into action, comprising a member mounted to rotate with theflshaft and arranged to be thrown outwardly when the shaft 1s rotating above a predetermlned' speed, a brake Wheel mounted to .rotate freely during the normal rotat on of the shaft and arranged to-be engaged by said memberupon outward movement thereof to cause the brake wheel to rotate with said member, means to withdraw said member from engagement with the brake wheel when the, shaft is rotating at or below the predetermined speed, a brake for retarding the rotation offthe brake wheel, and means to apply the brake to the brake wheel before the arresting m'echanismis brought into action, substantially as described.

12.- A stop mechanism, having,in'combi-i nation, a shaft, mechanism for arresting the forward rotation of the shaft, and a centrifugal brake device acting to slow down the shaft to a predetermined speed and then to release the shaft before the arresting mechanism is brought into operation, sub stantially as described.

13. A stop mechanism, having, in combination, a shaft, IIIGClHlIIiSIH'fOI arresting the. forward rotation of the shaft, means to throw the said mechanism into and out of operating position comprising a pivoted lever arranged whenin one position to maintaiii said arresting mechanism out of operating position and when in another position to permit the arresting mechanism to be thrown into operating position, an arm on said lever, a reciprocatory catch member arranged to engage said arm to prevent move ment of" said lever in a direction to permit the arresting mechanism to be thrown into operation, and means to move said reciprocatory member out of engagement with said arm'at a definite point in each rotation of the shaft, substantially as described. v 14. A stop mechanism, having, in combination, a shaft, mechanism for arresting the forward rotation of the shaft and" for imparting thereafter a return movement thereto comprising an oscillatory lever having a cam surface formed thereon and arranged to v ranged to engage thelever'and move said lever about its axisin one direction, a rebound device acting to yieldinglyarrest the' said movement of the lever and then to move longitudinally of its axis, a member mounted to rotate with the shaft and a move said-lever inthe opposite direction to impart a return movement to the shaft 'comprising a cylinder, a piston operatingin the cylinder and connected with the lever,

,means to move said lever longitudinally of its axisinto and out of the path of said 1 means to move the second lever about its axls in one direction'to engage the secondmember with said cam and to move the first member comprising a cam carried by said lever, a second lever, a member, carried thereby for engagement with the said cam,

imparting thereafter areturn movement thereto, a brake device arranged to slow the shaft down to the predetermined speed.

and then to release the shaft, means under control of the operator to apply the brake,

and mechanism tripped by the action of said means in applying the brake and acting to bring the arresting mechanism into action at a definite point in a rotation of the shaft and at least a predetermined interval after the brake is applied, and means to arrest the return movement of the shaft at a definite position, substantially as described. I

16, A stop mechanism, having, in combination, a shaft, anoscillatory lever having a cam surface formed thereon and arranged to move longitudinally of its axis, a roll arranged to rotate with the shaftfor engagement with the cam surface of said lever, a spring for moving said lever into the path of said roll, a cam carried by the first lever, a second lever, a member carried by the second lever and arranged to engage said cam and move the firstlever longitudinally of its axis out of the path of said roll, an arm on the second lever, a catch member for engagement with said "arm to prevent movement of the second lever in a direction to permit the first lever to be moved into the path of said roll, means to move said catch member out ofthe path ofsaid arm at a definite point in a revolution of the shaft,

a brake for. arresting the return movement" of the shaft at a definite constant position,

an arm carried by the second lever formoving the brake out of operative posltion up -3n movement of the second lever in' a C direction to throw the first lever out of the movement thereto, .a bra path of the roll, and means to throw the brake into operative position whenthefirst lever is moved into :the" path of said roll, substantially as described. I v

l7. Astop mechanism, having, in combination, a shaft, a rebound device for yieldingly arresting theforward rotation of the shaft and-for thereafter 'iniizparting a return e for arresting the return movement of the shaft ,at-a definite constant position, a lever arranged when in one position to maintain said device and said brake out of operative position and when in another position tov permit said device and said brake to be thrown into operative position, a treadle and con-' nections therefrom for moving said lever from the second to the first position, a spring formoving saidlever from, the first to the second position, a latch for maintaining the lever in the first position until the treadle is completely released, and" means to disengage said latch upon the complete release "of the treadle, substantially as described 18. A stop mechanism, having, in combination, a shaft, rebound devices for arresting the forward rotation of the shaft and for imparting thereafter a return movement to the shaft, a brake device to slow the'shaft down to a predetermined speed and then to release the shaft, means to apply the brake upon the release of the treadle,

and mechanism tripped by the release of the treadle and I acting automatically to bring the rebound devices into action at a predetermined point in the rotation of the shaft and at least a predetermined interval after the brake is applied, substantially as described. I f

19. A stop mechanism, having, in combination, a shaft, rebound devices for arresting the forward rotation'of the shaft and for imparting thereafter a return movement to the shaft, a brake device to slow the shaft down to a predetermined speed and then to release the shaft, meanslto apply, the brake upon the release of the treadle, mechanism tripped by the release of the treadle and acting automatically to bring the rebounddevices into action at a predetermined point inthe rotation of the shaft and at least a predetermined interval, after the brake is applied, and means to throw the .rebound devices out of relative operating positions and simultaneously to release the brake upon the depression of the treadle,

substantiallv as described.

nation, a shaft, a main driving mechanism therefor, speed reducing mechanism ren- 12 dered active when-the main driving mechanism is thrown out, means for rendering the speed reducing mechanism inactive allowing the shaft to continue its rotation under its momentum, and mechanism for stopping the shaft after the speed'reducing mechanism becomes inactive.

21. A stop mechanism having in combination a shaft, a main driving mechanism therefor, speed reducing mechanism rendered active when the main driving mechanism is thrown out, means for rendering the speed reducing mechanism inactive, and

' rebound mechanism acting after the speed reducing mechanism becomes inactive to arrest the forward rotation of the shaft and turn the shaft back to stopping position.

22. A stop mechanism, having in combination, a shaft, a main driving mechanism therefor, a friction brake rendered active when the main driving mechanism is thrown out, means for rendering the brake inactive when the speed of the shaft has been reduced to a certain point'and rebound mechanism, acting to arrest the forward rotation of the shaft and turn the shaft back to stopping position.

23. A stop mechanism having in combination, a shaft, a main driving mechanism therefor, a friction brake rendered active when the main driving mechanism is thrown out, means for rendering the brake inactive when the speed of the shaft has been reduced to a certain point, rebound-mechanism acting after the brake is inactive to arrest the forward rotation of the shaft and turn the shaft back to stopping position after it is freed from the brake, and means for insnring at least a predetermined interval between the application of the brake and the action of the rebound mechanism.

24:. A stop mechanism having in combination a shaft, a main driving mechanism therefor under control of the operator, mechanism rendered active when the main driving mechanism is thrown out by the operator for slowing down the shaft to a predetermined speed and mechanism acting initially while the shaft is rotating at the reduced speed to arrest the forward rota- V tion of the shaft and turn it back to stopping position. v

25. A stop mechanism having in comhination, a shaft;a main driving mechanism therefor under control of the operator, mechanism rendered active when the main driving mechanism is thrown out by the operator for slowing down the shaft to a predetermined speed and rebound mechanism acting initially while the shaft is rotating at the reduced speed to arrest the forward rotation of the shaft and turn it back to stopping position.

26. A stop mechanism having in combination a shaft, driving mechanism for the shaft, speed controlled speed reducing mechanism rendered active when the driving mechanism is thrown out, and mechanism for throwing out the speed reducing mechanism when the speed is reduced to a predeterand inactive when the speed of the shaft has been reduced to a predetermined point,

and means for stopping the shaft after the brake is inactive.

29. A stop mechanism having in combination a shaft, driving mechanism for the shaft, a centrifugal brake device arranged to slow the shaft down to a predetermined speed, and then to release the shaft, and means acting to apply the brake when the driving mechanism is thrown out. I

' WILLIAM C. STEWART. Witnesses:

ERIo A. HoLMenEn, NORMAN C. HUssEY.

fiopiea of this patent may be obtained for five cents each, by addressing the commissioner oi Barents,

- Washington, DAL 

